Attachment for lathes



Jan. 29, 1952 J. WIEGANT 2,583,917

INVENTOR. JOHN WIE GANT ATTOR NEY Jan. 29, 1952 J. WIEGANT ATTACHMENT FOR LATHES 2 SHEETS-SHEET 2 Filed April 17, 1950 INVENTOR.

JOHN WIEGANT BY ATTORNEY Patented Jan. 29, 1952 UNITED STAT ES PAT ENT OFF ICE ATTACHMENT FOR. LATHES: John Wiegant, Depoe Bay, Greg.

Application April 17, 1950; SerialNoi 156,307

l Glaim; (CI. 90-59 )5 This invention relatesvin general to attachments. for ordinary lathes, and, more: specifically, to an. attachment. adapted to enable a. milling operation, such as. the cutting of a key-way in a shaft, to be performed on a lathe.

A particular object. of the invention. is. to provide a: lathe. attachment by the aid of which a milling operation can be performed. on a lathe withthe use of a common end mill cutter.

A further object of the. invention is. tov provide an. attachment for use; on. a lathe. which will enable keyways to be. cut. to. any size, depth. and length in shafts:- cf a. wide: range of sizes merely by the" use of common end mill cutters.

An additional: object of this invention is. to provide an attachmentserving the purpose above indicatedfor ordinary lathes, which attachment will be simple and practical inconstruction, relatively inexpensive to manufacture, and easy to use; thereby enabling the owner of an: ordinary lathe to perform such operations. as cutting key- Ways in shafts, which would otherwise be re.- quired tobe doneon a separate milling machine.

The manner in which theseobjects are. attained with my special attachment for lathes will be readily understood from the following brief description of the attachment, in which description reference is to be'made to the accompanying drawings.

In the drawings:

Fig. 1 is a perspectiveview ofmy lathe attachment by itself;

Fig; 2 is a side elevation of the same, drawn to a larger scaleand illustrating how a shaft is held bythe attachment;

Fig. 3 is a fragmentary plan view of a lathe with my attachment mounted on the lathe and illustrating" the same in use in the cutting of a keyway in a shaft-.by-ani ordinarvend mill cutter; and

Fig. 4 is a corresponding side elevation, taken from the leftin Fig; 3.

The main body member of my lathe attachment comprises a cast block I preferably shaped substantially as shown in Figs. 1 and 2. This block has a front face having separated upper and lower sections II and I2 which lie in the same plane perpendicular to the bottom face l3 of the block. A V-shaped groove, the faces of which preferably form a dihedral angle of 90, extends horizontally across the front face of the block. The two faces l4 and I5 of the groove make equal angles (thus preferably angles of 225') with the adjacent front face sections II and L2 respectively, and the vertex line l6 of the groove is horizontal and is. parallel. to; the plane of the. front face sections ll andi [218.8 well as being parallel to the bottom face: t3.

A hole extends vertically through. the. block: [0 to accommodate a. bolt H The bottom end of the bolt is enlarged and formed into a clamping. plate I8 adaptedto be inserted. in either end of the channel I9 (Figs. 3 and 4')= extending trans.- versely across the lathe carriage 20', which; channel is customarily used for the tool post of the lathe, and tobe adjustabl y positioned therein. A n-ut 2|, at the top ofthe bolt. t1, enables the block Ill to be secured on the lathe carriage 20 bycausing a clamping action to be exerted between the nut and the plate- [8 on the block- Hi and interposedportion of" the top of the lathe carriage.

A pair of cars 22 extend an opposite sides respectively from the upperportion of theblock if). A threaded stub shaft 23* (Fig. 2) extends through a channel in each of these cars '22 and carries a tightening nut 24 placed against the rear face of. each ear. The forward end of each stub. shaft 23, beyond the front face of each ear 22, is: connected to a sprocket chain 25. A pair of spaced. fingers 26 are mounted on each side of the lower portion of the block "if. The spacing between each pair of fingers 26' is such as to enable a link of one ofthe' sprocket chains 24, when. inserted between the fingers, to be held firmly against any pull on the chain, as will be apparent-from Figs. 1, and2.

The function of; the sprocket. chains 25 and their mountings. is to enable. a. shaft, such as. the shaft. 21 of Figs. 2,..3. and 4, to. be firmly held against. the front. face of, the. block L0 and in the horizontal. transverse, groove of the block. The two. chains. at oppositesides of the block Hi can havetheir free. ends adjusted intheir respective: pairs of; fingers. 2.6. so as to. provide. chain loops of. the. desired. size. to fit. around. the shaft tobe: held in place, such. as the shaft, 21., where.- upon the final tightening of the chains, done by means of the tightening nuts 24, will cause the shaft to be very firmly held in place in the groove on the front face of the block I0. Thus shafts of a wide range of diameters may be secured to the block ID in this manner, and, when the holding chains 25 are properly tightened, the shaft will then always be held with its axis exactly in the same horizontal plane as the vertex line It of the transverse V-shapcd groove of the block [0.

The distance of the vertex line Hi from the bottom face l3 of the block l0, and thus the 3 distance of the vertex of the groove from the top of the lathe carriage 20 (Fig. 4), is such that this vertex line IE will be exactly in the same horizontal plane as the axis of the rotating head and chuck 28 of the lathe and consequently also in the same horizontal plane as the axis of any cutting tool, such as the end mill cutter 29, mounted in the lathe chuck.

When myattachment is to be used for example in the-cutting of a keyway in a shaft, the attachment is 'mounted" on the lathe carriage 20 in place of the usual tool post and is secured to the carriage by the tightening of the nut H. The carriage 20, as is customary in all ordinary lathes, can be moved transversely on the lathe,

4 attachment and a minimum amount of adjustment is required.

Minor modifications could of course be made in my lathe attachment without departing from the principle of my invention, but the particular manner of constructing my attachment which I have illustrated and described I consider to be preferable.

I claim:

.' A lathe attachment of the chara te described,

adapted to be mounted'on a'la'the carriage in place of the tool rest, said attachment including 'a body block having a flat bottom face and a thus by means of an adjustable positioning screw operated by the hand control 3 0 (Figs. 3 and 4) or the entire carriage assembly can be moved longitudinally with respect to the lathe'by opriage 20 theshaft onwhich the work is to be 1 done, such as the shaft 21 shown in the drawings, is then firmly secured to the block [0 by means of the chains 25 and the tightening nuts 24. The end mill cutter 29 of the proper diameter corresponding to the desired width of the keyway or slot to be cut in the shaft, is secured in the chuck of the lathe.

With the shaft 21 mounted in position on the block H! as desired, and the end mill cutter 29 rotating, thecarriage 20, with the block Iii and shaft thereon, is moved forwardly by means of the manual control 3| until the end mill cutter engages the shaft and cuts a hole to the desired depth for the slot or keyway. Then further forward movement of the carriage is discontinued and the carriage is next moved laterally or transversely by means of the control 30, thus causing the shaft 2'! to be moved along in an axial direction without changing its distance from the cutting tool, with the result that the end mill cutter 29 will out the longitudinal slot or keyway in the shaft as desired. Since the axis of the shaft 2! will always be in the same horizontal plane as the axis 'of the lathe chuck and cutting tool, the resulting slot in the shaft will always extend parallel to the shaft axis.

any'width, depending upon the cutting tool selected, can be cut in any shaft on any ordinary lathe with the use of my attachment. Therequirement for a separate milling machine for the performance of such work is eliminated, and no tool beyond the ordinary end mill cutter is required. My attachment can quickly and easily be set in place on the lathe carriage and subsequently removed therefrom, in place of the ordinary tool post. The shaft, or other object on which the work is to be done, is quickly and easily secured in proper position on the lathe Thus a slot of any depth and length'hnd of r front face perpendicular to said bottom face, said bottom face adapted to rest on the top of said carriage, a clamping bolt extending centrally downwardly through said block, a clamping plate on the bottom end of said bolt and spaced below said bottom face of said block for engaging the tool-rest-mountinggroove in said carriage, a clamping'nut on theupper end of said bolt on top of said block, a V-shaped groove extending across said front face. of said block, the walls of said groove forming equal angle with the top and bottom portions of said front face respectively, the vertex line of said groove extending parallel to said bottom face of said block and located at such distance from said bottom face that when said block is mounted on said carriage said vertex line will lie in the same horizontal plane as the axis of rotation of the lathe tool, a pair of spaced fingers extending laterally from each side of said block below said groove, a pair of sprocket chains having bottom end portions removably engaged by said pairs of fingers respectively, an ear extending from each side of said block above said groove, a channel extending through each ear, a threaded stud shaft attached to the upper end of each chain, said stub shafts extending through said ear channels respectively, and a tightening nut on each stub shaft, whereby said chains can hold the work clamped in said groove on said attachment and said block will hold the work in desired position on said carriage and lathe.

JOHN WIEGANT.

REFERENCES CITED 7 The following references are of record in the file of this patent:

UNITED STATES PATENTS Denmark Dec. 11, 1918 

